1. Field of the invention
The present invention relates to a process for producing 4-carbonyloxyquinoline derivatives useful as agricultural chemicals.
2. Background Art
4-Carbonyloxyquinoline derivatives are disclosed as compounds that are useful as agricultural and horticultural insecticides or agricultural and horticultural fungicides in WO2006/013896 (patent document 1), Japanese Patent Application Laid-Open Publication No. 110953/2008 (patent document 2), and WO2007/088978 (patent document 3). These 4-carbonyloxyquinoline derivatives are compounds having high insecticidal activity against Lepidoptera, Hemiptera, Coleoptera, Acari, Hymenoptera, Orthoptera, Diptera, Order Thysanoptera, and plant parasitic nematodes. Further, the 4-carbonyloxyquinoline derivatives are known as agricultural and horticultural insecticides fungicides that are effective against various plant pathogenic fungi, for example, exhibit fungicidal effects against Sphaerotheca fuliginea, Puccinia recondita f. sp. tritici, Blumeria graminis, Alternaria solani, Venturia inaequalis, Monilinia fructicola and Glomerella cingulata. A process for producing the 4-carbonyloxyquinoline derivatives is disclosed in WO2010/007964 (patent document 4).
This patent document discloses a process for producing 4-carbonyloxyquinoline derivatives that includes reacting a quinolone derivative with a halogenated compound or an acid anhydride in the presence of a base. Bases such as sodium hydride and sodium-t-butoxide used in this process are highly reactive and hygroscopically decomposable and thus are difficult to handle. Accordingly, close regulation of charging equivalent is necessary to avoid the decomposition of the product. In addition, bases such as sodium hydride and sodium-t-butoxide are expensive. Therefore, a further improvement as a commercial industrial process is demanded. Further, when bases such as sodium hydride and sodium-t-butoxide are used, a large amount of high-boiling amide solvents such as dimethyl acetamide should be used as the reaction solvent. Further, in the isolation of the 4-carbonyloxyquinoline derivatives, a larger amount of water should be added. Accordingly, there is a possibility that the operation efficiency is lowered in the isolation of the product. Contamination of a large amount of the amide solvent into waste water causes a large load on waste water, and the solvent should be recovered from the aqueous solution. However, due to high boiling point, a large amount of energy that is sometimes disadvantageous in industrial production, is necessary for the recovery of the solvent.
Accordingly, it can be said that the development of a more advantageous industrial process for producing 4-carbonyloxyquinoline derivatives that have been found to be useful as insecticidal compounds and fungicidal compounds has been desired.